Absorption measurements of liquid crystals in the ultraviolet, visible, and infrared

Complete absorption spectra of three liquid crystals with different conjugation length were measured in the 0.185–20 μm spectral range. In the ultraviolet region, the absorption is dependent on whether σ or π electrons are involved. In the mid and long infrared regions, several localized molecular vibration bands exist. The saddle absorption minimum occurs at around λ∼0.8 μm that is far from the electronic resonance and is right before the overtone molecular vibration begins.